Heater Hose: Service and Repair

The heater hose inlet pipe (37) and heater hose outlet pipe (36) extend forward from the dash front panel next to the heater module. The heater hose inlet pipe (37) is toward the left side of the vehicle from the heater hose outlet pipe (36).

On the 3800 (VIN K) engine, the heated coolant supply for the heater comes from a quick connect fitting (33) at the serpentine belt tensioner, just below the generator. A tube from the fitting extends across the front of the engine and connects to a heater inlet pipe (37) that is mounted on the right side rail in the engine compartment. The rear end of the pipe is connected to a short inlet hose that leads to the heater core.

On both engines, the heater hose outlet pipe (36) discharges coolant to a short heater outlet hose that is connected to a pipe mounted on the right side rail in the engine compartment. The forward end of the pipe is connected to an outlet hose that crosses in front of the engine and feeds the coolant into the water pump 5.7L (VIN P) or the serpentine drive belt tensioner 3800 (VIN K).

Remove or Disconnect

1. Engine coolant
^ Drain enough coolant into a clean container for reuse.

NOTICE: The heater core can be damaged if excessive force is applied on the core pipes during hose removal.

NOTICE: Heater hose quick connect fittings are designed to be removed - by hand. Do not attempt to pry quick connect fittings from the drive belt tensioner or damage may result.

2. Heater hoses and heater hose pipes (33 and 146) If replacing only heater hose, cut the crimp at heater hose pipe and replace it with a worm gear clamp.
A. Twist and pull quick connect fittings (27) from drive belt tensioner.
^ Discard O-rings.
B. Squeeze clamps with pliers and slide clamps away from heater core fittings.
C. Bolt/screw (29) mounting heater hose pipes (36 and 37) to side rail.
D. Remove heater hose and heater hose pipes from heater core by gently twisting and pulling.

Install or Connect

1. Heater hose and heater hose pipes (33 and 146)
A. Squeeze clamp ends and slip new hose clamps over ends of heater hoses.
B. Install heater hoses to heater core.
^ Apply rubber lubricant to inside diameter of hoses, if necessary.
C. Bolt/screw (29) mounting heater hose pipes (36 and 37) to side rail.

Tighten

^ Heater inlet and outlet pipe bolt/screw (29) to 14 N.m (10 lb. ft.).
D. O-rings to quick connect fittings.
E. Snap quick connect fittings to drive belt tensioner
^ Pull back on quick connect fittings to verify proper connector engagement.
2. Engine coolant.
^ Use coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture.

Inspect

^ Be sure installed hose does not sag or rub against other components. Adjust or support hose as necessary to correct hose position.
^ Operate engine and check hose installation for leaks.
^ Check coolant level after engine has been warmed up. Add coolant as necessary.